Thermo-electric fire-alarm system.



A. IVI. D SlLVA GREAVES.

THERMO ELECTRIC FIRE ALARM SYSTEM.

APPLICATION FILED JUNE Il, 1914.

Patented Deo'. 25, 1917.

UNITE THERMO-ELECTRIC FERR-ALARM. SYS'CEII.

Application tiled June il, i914.

To all whom it may concern; r

Be it known that I, Animo MARIA nia SILVA GREAvEs, a citizen of theRepublic of Portugal, residing at Cambridge7 in the county of Middlesexand State of Massa ehusetts, have invented certain neu7 and usefulImprovements in Thermo-Electric Fire- Alarm Systems, of which thefollowing is a specification.

into said chamber or chambers in such a.

manner as to be enveloped by the expanding mercury as the same entersthe chamber or chambers so as to effectively close circuit and energizethe alarm.

A further object islto adjustably mount vthe terminals so that they maybe projected into the expansion chambers to a greater or less extentthereby Varying the time at which the alarm is energized but alwaysinsuring an effective electrical contact with the Aiercury irrespectiveof the position of the terminals in said chambers.

A further and every special object of the invention is to increase thecross section of the expansionl chamber or chambers from their lowertoward their upper portions so that adjustment of the terminals upwardlywill retard energization of the alarm while a reverse adjustment o't the'terminals downivardly will ad'- ance such energization.

Other objects and features of the invention will be more fully describedin connection with the accompanying drawing and will be moreparticularly pointed out and ascertained in and by the appended claims.

In the drawingz Figure 1 is a View; partly diagrammatic, illustratingthe preferred form of my invention electrically connected up with analarm device.

Fig. 2 is a vertical. sectional view(` of the l preferred constructionof circuit closer.

Like characters reference designate Specification of Letters atent.

Serial Sil/MFH?.

, similar parts throughout the diiierent figures or" the drawings tReferring more particularly to Fig, i, an alarm system is shownincluding a mercury circuit closer, having terminals i? and 3 connectedwith conductors l und 5, respectively, of an clarin circuit. Corniuctorl is`,connectcd 'with one pole of a source ot curreiat indicteegl at tijand the other 'pole of said source of current is connected by aconductorT'witn an alarm device which may be in the forni of an elec* tric bell8. The connection of conductor C" with the alarm device S is indicatedat 9, land conductor 5 is connected with theV alarm. device indicated ati0.

in vieu' oi' the fact that the device of my' invention relatos to thecircuit closer7 the latter is only shown in one figure connected, upYwith the circuit. as the application to the circuit ot other forms ofmy invention will be clearly understood to those skilled in the art. j

Referring more particularly to Fig. 2, which illustrates the preferredconstruction5 'il designates a suitable hase upon which. the tube 1:2may he secured h v means such as a clip i3, The tube l2 is provided witha reduced bore ill which terminates at its lower end in a bulli l5 andwhich is o t suilicieu't length to provide ii'or considerable expansionindicated as a whole at il of the mercury in the horc il above pointsnormal temperature. The tuhc i2 will pref crably he oi glass and abovethe elevations of normal temperature to which the mercury may rise. thetube i2 is provided with an enlargement i6 which converges, as indicatedat i7, toward the normal cross section of the bore i4, rlhe enlargementii provides for an expansion of the mercury when it enters the chamberthereby reducing' rapidity ci" its ascent from the time that theexpanding mercury roaches the divcrfring Vall portions i? oftheexpansion chamber9 for a purpose which will presently appear. The tube12 is provided with a downiardly converging partition i8v having apointed end itl which extends a suliicient distance downwardly toapproximately approach the noi-meri cross section of the bore 14- butnot lift minating immediately above the bore of said tube, extensionsformed with said expansion chamber and havingr bores communicating withthe latter at opposite sides of said partition, terminals supportedwithin the bores of said extensions and depending within said 'expansionchamber, the lower ends of said terminalsbeing curved into vclose prof!A pansion chamber formed at the upper end of said tube and communicatingwith said bore, extensions formed with said expansion chamber andhavingr bores communicating with the latter, the walls of said expansionchamber curving outwardlyv from opposite sides cof the bore of said tubeand upwardly permanently bowed and spaced from the opto the Lores ofsaid extensions, a triangular shaped partitiondepcnding within said exnpansion' vchamber and having its oppositely inclined walls extendingfrom the ,bores of said extensions to a point immediately above the boreof said tube, terminals supported within the bores of said extensionsand projecting into said expansion chamber, the `ower end portions ofsaid terminals being posed Walls of said Vexpansion chamber and saidpartition, and means for adjusting said terminals Within said expansionchamber, the curved ends of said terminals engaging the inclined Wallsof said partition, during 4" the adjusting movement, to further bow thecurved portions thereof, whereby to free the same from such particles ofthe mercury adhering thereto.

In-testirnony whereof I aiix my signature 45 in presence of twowitnesses. ABILIO MARIA DA SILVA GREAVES.

, Witnesses: 7 AUGUSTO J. Taverna, ARTHUR J. Tarrina.

